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PSLV-C33
IRNSS-1G was the seventh and final of the Indian Regional Navigation Satellite System (IRNSS) series of satellites after IRNSS-1A, IRNSS-1B, IRNSS-1C, IRNSS-1D, IRNSS-1E and IRNSS-1F. This system of satellites will provide navigational services to the Indian region. The satellite was launched successfully on 28 April 2016 at 07:20 UTC. IRNSS-1G along IRNSS-1A is being used only for NavIC's short message broadcast service and not for navigation. Launch The satellite was launched from the First Launch Pad (FLP) of Satish Dhawan Space Centre, Sriharikota on board PSLV-C33 XL on 28 April 2016 at 12:50 PM IST. The countdown of the launch had begun 51:30 hours before at 9:20 AM IST on 25 April 2016. After the launch of IRNSS-1G the Indian government named the IRNSS system as NAVIC (Navigation with Indian Constellation). Specifications Mission life: 12 years (planned). Lift-off mass: Dry mass: . Payload: CDMA ranging payload in C band. Navigation payload in L-5 and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSLV-C32
IRNSS-1F is the sixth navigation satellite out of seven in the Indian Regional Navigational Satellite System (IRNSS) series of satellites after IRNSS-1A, IRNSS-1B, IRNSS-1C, IRNSS-1D and IRNSS-1E. The satellite is one among the seven of the IRNSS constellation of satellites launched to provide navigational services to the region. Launch It was launched aboard a PSLV-XL rocket bearing flight number C32 and was successfully put into geosynchronous orbit at 1601 hrs IST on 10 March 2016. Spacecraft The satellite carries two types of payloads. The navigation payload transmit navigation service signals to users and ranging payload consists of C-band transponder that facilitates accurate determination of the range of the satellite. It carries Corner Cube Retro Reflectors for laser ranging. IRNSS-1F has a 12-year mission life. See also * Communication-Centric Intelligence Satellite (CCI-Sat) * GPS-aided geo-augmented navigation (GAGAN) * Satellite navigation A satelli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IRNSS-1F
IRNSS-1F is the sixth navigation satellite out of seven in the Indian Regional Navigational Satellite System (IRNSS) series of satellites after IRNSS-1A, IRNSS-1B, IRNSS-1C, IRNSS-1D and IRNSS-1E. The satellite is one among the seven of the IRNSS constellation of satellites launched to provide navigational services to the region. Launch It was launched aboard a PSLV-XL rocket bearing flight number C32 and was successfully put into geosynchronous orbit at 1601 hrs IST on 10 March 2016. Spacecraft The satellite carries two types of payloads. The navigation payload transmit navigation service signals to users and ranging payload consists of C-band transponder that facilitates accurate determination of the range of the satellite. It carries Corner Cube Retro Reflectors for laser ranging. IRNSS-1F has a 12-year mission life. See also * Communication-Centric Intelligence Satellite (CCI-Sat) * GPS-aided geo-augmented navigation (GAGAN) * Satellite navigation A satelli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSLV-C34
PSLV-C34 was the 36th mission of the PSLV, PSLV (Polar Satellite Launch Vehicle) program and 14th mission of PSLV in PSLV-XL, XL configuration. The PSLV-C34 successfully carried and deployed 20 satellites in the Sun-synchronous orbit. With a launch mass of and payload mass of , the C34 set a new record of deploying the maximum number of satellites by Indian Space Research Organisation in a single mission. The PSLV-C34 carried One Cartosat-2 satellite, SathyabamaSat (satellite from Sathyabama University, Chennai), Swayam (satellite from College of Engineering, Pune) & 17 other satellites from United States, Canada, Germany & Indonesia. Mission parameters * Mass: ** ''Total liftoff weight:'' ** ''Payload weight:'' * Overall height: * Propellant: ** ''Stage 1:'' Solid-fuel rocket, Solid Hydroxyl-terminated polybutadiene, HTPB based ** ''Stage 2:'' Liquid fuel rocket, Liquid UH 25 + ** ''Stage 3:'' Solid-fuel rocket, Solid Hydroxyl-terminated polybutadiene, HTPB based ** ''Stage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite Navigation
A satellite navigation or satnav system is a system that uses satellites to provide autonomous geo-spatial positioning. It allows satellite navigation devices to determine their location (longitude, latitude, and altitude/elevation) to high precision (within a few centimetres to metres) using time signals transmitted along a line of sight by radio from satellites. The system can be used for providing position, navigation or for tracking the position of something fitted with a receiver (satellite tracking). The signals also allow the electronic receiver to calculate the current local time to a high precision, which allows time synchronisation. These uses are collectively known as Positioning, Navigation and Timing (PNT). One set of critical vulnerabilities in satellite communications are the signals that govern positioning, navigation and timing (PNT). Failure to properly secure these transmissions could not only disrupt satellite networks but wreak havoc on a host of dependent s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spacecraft Attitude Control
Spacecraft attitude control is the process of controlling the orientation of a spacecraft (vehicle/satellite) with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc. Controlling vehicle attitude requires sensors to measure vehicle orientation, actuators to apply the torques needed to orient the vehicle to a desired attitude, and algorithms to command the actuators based on (1) sensor measurements of the current attitude and (2) specification of a desired attitude. The integrated field that studies the combination of sensors, actuators and algorithms is called guidance, navigation and control (GNC). Overview A spacecraft's attitude must typically be stabilized and controlled for a variety of reasons. It is often needed so that the spacecraft high-gain antenna may be accurately pointed to Earth for communications, so that onboard experiments may accomplish precise pointing for accurate collectio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monomethylhydrazine
Monomethylhydrazine (mono-methyl hydrazine, MMH) is a highly toxic, volatile hydrazine derivative with the chemical formula . It is used as a rocket propellant in bipropellant rocket engines because it is hypergolic with various oxidizers such as nitrogen tetroxide () and nitric acid (). As a propellant, it is described in specification MIL-PRF-27404. MMH is a hydrazine derivative that was once used in the orbital maneuvering system (OMS) and reaction control system (RCS) engines of NASA's Space Shuttle, which used MMH and MON-3 (a mixture of nitrogen tetroxide with approximately 3% nitric oxide). This chemical is toxic and carcinogenic, but it is easily stored in orbit, providing moderate performance for very low fuel tank system weight. MMH and its chemical relative unsymmetrical dimethylhydrazine (UDMH) have a key advantage that they are stable enough to be used in regeneratively cooled rocket engines. The European Space Agency (ESA) has attempted to seek new options in terms o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multi-junction Solar Cell
Multi-junction (MJ) solar cells are solar cells with multiple p–n junctions made of different semiconductor materials. Each material's p-n junction will produce electric current in response to different wavelengths of light. The use of multiple semiconducting materials allows the absorbance of a broader range of wavelengths, improving the cell's sunlight to electrical energy conversion efficiency. Traditional single-junction cells have a maximum theoretical efficiency of 33.16%. Theoretically, an infinite number of junctions would have a limiting efficiency of 86.8% under highly concentrated sunlight. As of 2008 the best lab examples of traditional crystalline silicon (c-Si) solar cells had efficiencies between 20% and 25%, while lab examples of multi-junction cells have demonstrated performance over 46% under concentrated sunlight. Commercial examples of tandem cells are widely available at 30% under one-sun illumination, and improve to around 40% under concentrated sunlight. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubidium Atomic Clock
A rubidium standard or rubidium atomic clock is a frequency standard in which a specified hyperfine transition of electrons in rubidium-87 atoms is used to control the output frequency. Synopsis The Rb standard is the most inexpensive, compact, and widely produced atomic clock, used to control the frequency of television stations, cell phone base stations, in test equipment, and global navigation satellite systems like GPS. Commercial rubidium clocks are less accurate than caesium atomic clocks, which serve as primary frequency standards, so the rubidium clock is a secondary frequency standard. All commercial rubidium frequency standards operate by disciplining a crystal oscillator to the rubidium hyperfine transition of 6.8 GHz (). The intensity of light from a rubidium discharge lamp that reaches a photodetector through a resonance cell will drop by about 0.1% when the rubidium vapor in the resonance cell is exposed to microwave power near the transition frequency. The cryst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S Band
The S band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a part of the microwave band of the electromagnetic spectrum covering frequencies from 2 to 4 gigahertz (GHz). Thus it crosses the conventional boundary between the UHF and SHF bands at 3.0 GHz. The S band is used by airport surveillance radar for air traffic control, weather radar, surface ship radar, and some communications satellites, especially those used by NASA to communicate with the Space Shuttle and the International Space Station. The 10 cm radar short-band ranges roughly from 1.55 to 5.2 GHz. The S band also contains the 2.4–2.483 GHz ISM band, widely used for low power unlicensed microwave devices such as cordless phones, wireless headphones (Bluetooth), wireless networking (WiFi), garage door openers, keyless vehicle locks, baby monitors as well as for medical diathermy machines and microwave ovens (typically at 2.495 GHz). India's re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
L Band
The L band is the Institute of Electrical and Electronics Engineers (IEEE) designation for the range of frequencies in the radio spectrum from 1 to 2 gigahertz (GHz). This is at the top end of the ultra high frequency (UHF) band, at the lower end of the microwave range. Applications Mobile service In Europe, the Electronic Communications Committee (ECC) of the European Conference of Postal and Telecommunications Administrations (CEPT) has harmonized part of the L band (1452–1492 MHz), allowing individual countries to adopt this spectrum for terrestrial mobile/fixed communications networks supplemental downlink (MFCN SDL). By means of carrier aggregation, an LTE-Advanced or UMTS/HSDPA base station could use this spectrum to provide additional bandwidth for communications from the base station to the mobile device; i.e., in the downlink direction. In the Americas, mobile services are operated between the 1.7 GHz to 2.1 GHz range in the PCS and AWS bands. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C Band (IEEE)
The C band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a portion of the electromagnetic spectrum in the microwave range of frequencies ranging from 4.0 to 8.0 gigahertz (GHz). However, the U.S. Federal Communications Commission C band proceeding and auction, designated 3.7–4.2 GHz as C band. The C band is used for many satellite communications transmissions, some Wi-Fi devices, some cordless telephones, as well as some Radar and weather radar systems. Use in satellite communication The communications C band was the first frequency band that was allocated for commercial telecommunications via satellites. The same frequencies were already in use for terrestrial microwave radio relay chains. Nearly all C-band communication satellites use the band of frequencies from 3.7 to 4.2 GHz for their downlinks, and the band of frequencies from 5.925 to 6.425 GHz for their uplinks. Note that by using the band from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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